Oxygen

Oxygen is one of the Resources in the game Oxygen Not Included. It is a Breathable Gas and required by Duplicants to survive. It can be produced by machines (Oxygen Diffuser, Electrolyzer, Rust Deoxidizer), filtered from Polluted Oxygen by Deodorizers or cooling to liquid form, or a small amount created by the Algae Terrarium.

Mechanics
Oxygen is one of the lightest gases. Oxygen can be breathed in by Duplicants and exhaled as Carbon Dioxide. Due to the fact that Oxygen is lighter than Carbon Dioxide it will rise above it.

Although Duplicants require Oxygen to live, Oxygen is only breathable in high enough quantities (anything below 50 g/tile is unbreathable while anything between 50 and 300 g/tile is breathable but will stress Duplicants).

Duplicants typically use 100 grams of Oxygen per second (200 g/s with Mouth Breather trait, 75 g/s with Diver's Lungs, 50 g/s with Deeper Diver's Lungs, and 25 g/s with both). If the pressure is high enough they breathe normally, if it is non-breathable they will hold their breath until breath meter reaches 50%, then stop any task and run to closest spot to refill their lungs. If their breath meter reaches zero, they suffocate to death.

Usage

 * Atmo Suit, Jet Suit, Oxygen Mask, and Lead Suit Docks require Oxygen to (re)fill their respective suits.
 * The Telescope requires Oxygen to work.
 * The Oxylite Refinery produces Oxylite from Oxygen and Gold. 600 g/s Oxygen + 3 g/s Gold = 600 g/s Oxylite.
 * Puft Princes and Dense Pufts can breathe Oxygen and excrete Oxylite.
 * Longhair Slicksters consume 30 kg/cycle. and provide some mobile Decor.
 * When cooled down to liquid state, Liquid Oxygen is a better rocket oxidizer that can be used by Petroleum Engine and Hydrogen Engine.
 * Although Oxygen has properties that are subpar for fast heat exchanges, applications requiring slow heat exchanges are best performed with Oxygen flowing through a circuit, with Radiant piping at the heat source and the heat sink. For example, maintaining the temperature of the Hydrogen in the Ranch for Dreckos can be done by channelling a dedicated circuit through the Ranch with the heat sink being a cold biome; thus, the ranch will not need cooling via objects that may take up foreground space, e.g. Wheezeworts.
 * The main advantage of using Oxygen is that the Oxygen can just mix with any Oxygen that is outside the circuit if there is any maintenance or modification that has to be done to the piping while Oxygen is still in it.
 * Oxygen is also much more available than other gases.

Production

 * Natural Oxylite emits Oxygen. 5 tiles of Oxylite are guaranteed near the Printing Pod to provide Oxygen for the first few cycles.
 * Oxygen Diffusers produce Oxygen from Algae. Although this may seem efficient at the start, as the game progresses there is not as much Algae to use.
 * Electrolyzers produce Oxygen from Water. 1 kg/s Water = 888 g/s Oxygen + 112 g/s Hydrogen. The Hydrogen needs proper handling otherwise it will make the air unbreathable.
 * Rust Deoxidizer can produce Oxygen, Chlorine and Iron Ore from Rust and Salt. 750 g/s Rust + 250 g/s Salt = 570 g/s Oxygen + 30 g/s Chlorine + 400 g/s Iron Ore.
 * Algae Terrariums produce Oxygen from Water and Algae. They also consume a tiny amount of nearby Carbon Dioxide, if present. They do not require power, but can be made more efficient when near a light source.
 * Oxyferns produce Oxygen from Carbon Dioxide.
 * The Deodorizer purifies Polluted Oxygen into Oxygen using Sand or Regolith as a filtration medium.